{"cve":"CVE-2024-56638","nvd":{"published":"2024-12-27T15:15:23.527","modified":"2026-06-17T08:12:36.920","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nft_inner: incorrect percpu area handling under softirq\n\nSoftirq can interrupt ongoing packet from process context that is\nwalking over the percpu area that contains inner header offsets.\n\nDisable bh and perform three checks before restoring the percpu inner\nheader offsets to validate that the percpu area is valid for this\nskbuff:\n\n1) If the NFT_PKTINFO_INNER_FULL flag is set on, then this skbuff\n   has already been parsed before for inner header fetching to\n   register.\n\n2) Validate that the percpu area refers to this skbuff using the\n   skbuff pointer as a cookie. If there is a cookie mismatch, then\n   this skbuff needs to be parsed again.\n\n3) Finally, validate if the percpu area refers to this tunnel type.\n\nOnly after these three checks the percpu area is restored to a on-stack\ncopy and bh is enabled again.\n\nAfter inner header fetching, the on-stack copy is stored back to the\npercpu area.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/53c7314208c865086d78b4e88da53bc33da0b603","https://git.kernel.org/stable/c/7b1d83da254be3bf054965c8f3b1ad976f460ae5","https://git.kernel.org/stable/c/da5cc778e7bf78fe525bc90ec2043f41415c31d9"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:57:56.913276502+00:00"},"epss":{"cve":"CVE-2024-56638","score":0.00227,"percentile":0.13443,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}